Hydrorotor craft



March 24, 1964 F. D. REYNOLDS 3,125,981

HYDROROTOR CRAFT Filed June 4, 1963 11 Sheets-Sheet 1 INVENTOR. Benn/e15 0. PfVA/dlfi' F. D. REYNOLDS March 24, 1964 HYDROROTOR CRAFT ll Sheets-Sheet 2 Filed June 4, 1963 INVENTOR. Ffi/M/d/f D. ear/van I BYEFJ) Z March 24, 1964 F. D. REYNOLDS 3,125,931

HYDROROTOR CRAFT Filed June 4, 1965 ll Sheets-Sheet 3 INVENTOR. Fen/v05 D. Ram/a4 as F. D. REYNOLDS HYDROROTOR CRAFT March 24, 1964 iled June 4, 1963 ll Sheets-Sheet 4 5UP Gil/70H inii- I INVENTOR. flan/a5 D. ZiV/VQZDJ' BY {8 M F. D. REYNOLDS HYDROROTOR CRAFT 2/ g i I March 24, 1964 ll Sheets-Sheet 5 Filed June 4, 19 5 INVENTOR. FRANd/fi' D. .Pnvowfi BY f8 W March 24, 1964 F. D. REYNOLDS 3,125,981

HYDROROTOR CRAFT Filed June 4, 1963 11 Sheets-Sheet 6 INVENTOR. FfiA/Vd/J' 0. 2554/0105 AGIIVI' 11 Sheets-Sheet 7 F. D. REYNOLDS HYDROROTOR CRAFT March 24, 1964 Filed June 4, 1963 INVENTOR Flam/e15 D. karma)! March 24, 1964 Filed June 4, 1963 kaopeze F. D. REYNOLDS 3,

HYDROROTOR CRAFT ll Sheets-Sheet 8 INVENTOR. Fem 05' D. Ba r/V0405 March 24, 1964 F. D. REYNOLDS 3,125,981

HYDROROTOR CRAFT Filed June 4, 1965 11 Sheets-Sheet 1O nag/w- 7 March 24, 1964 F. D. REYNOLDS HYDROROTOR CRAFT ll Sheets-Sheet 11 Filed June 4, 19 3 Ill INVENTOR. #7610615 D. REV/V016 0.5 BY W xms/vr United States Patent 3,125,981 HYDRUROTQR QRAFT Francis D. Reynolds, Redmond, Wash, assignor to The Boeing Company, Seattle, Wash, a corporation "of Delaware Filed lune 4, 1963, Ser. No. 285,388 19 Claims. (tCl. 115-50) This invention relates to propulsion and support systems for craft movable over water and/ or land, and more particularly to such a system which utilizes at least one power driven rotor positioned below the craft for propulsion, support and steering thereof.

The conventional water craft comprises a bulky hull which, when propelled, plows through the water. The speed attainable is limited by the resistance to motion produced by the friction of the water on the hull of the craft, and various proposals have been made or used for reducing this resistance. Among these proposals have been the use of wheels, tracks, rollers, planing hulls and hydrofoils which function to raise the craft out of the water during high speed operation thus reducing the water resistance.

The instant invention provides a propulsion and support system for water craft which is particularly adapted to travel at high speed with substantially zero water resistmice. This result is obtained by supporting and propelling the craft by a novel system whereby the craft is raised out of the water and literally runs thereon at high speeds.

Therefore, an object of this invention is to provide a craft capable of traveling on water at high speeds.

A further object of the invention is to provide a craft capable of movement over water and land.

A still further object of the invention is to provide a system which supports and propels a water craft at high speeds.

Another object of the invention is to provide a propulsion system for water craft which utilizes at least one hydrorotor.

Another object of the invention is to provide a hydrorotor propulsion and support system for water craft which additionally functions for steering, reversing, and lateral movement of said craft at high speeds.

Another object of the invention is to provide a hydrorotor propulsion system for water craft which additionally functions to steer, reverse and laterally maneuver said craft at low speeds while the craft is buoyantly supported by the hull(s).

Another object of the invention is to provide a hydrorotor propulsion and support system for water craft which utilizes tilted conical shaped hydrofoil-bladed rotors.

Another object of the invention is to provide a hydrorotor propulsion and support system for water craft which utilizes tilted plane hydrofoil-bladed rotors.

Another object of the invention is to provide a water craft propulsion system utilizing tilted bladed hydrorotors and which changes the direction of reaction of the rotors against the water for steering and maneuvering the craft.

Another object of the invention is to provide water craft propulsion and support system utilizing a plurality of hydrorotors which are independently controlled as to speed, blade angle of attack, and surface reaction direction.

Another object of the invention is to provide a propulsion and support system for a craft which utilizes hydrorotors having means for varying the blade angle contact surface area.

Another object of the invention is to provide a propulsion and support system for a craft which utilizes a plurality of conical shaped rotors for water-borne operation and a plurality of traction and support means for land operation.

Other objects on the invention not specifically set forth above will become readily apparent from the following description and drawings in which:

FIG. 1 is a perspective view of a water craft incorporating the invention;

FIG. 2 is a schematic plan view of a craft utilizing the invention and showing the direction of rotation and contact area of the hydrorotors;

FIG. 3 is an end view of the FIG. 2 craft;

FIGS. 4A, 4B and 4C are views showing the rotor contact area of the FIG. 2 craft during high speed dynamically supported maneuvers;

FIGS. 5A, 5B, 5C and 5D are views showing the rotor positions of the FIG. 2 craft during buoyant-support lowspeed maneuvers;

FIG. 6 is a plan view of one embodiment of the invention showing the drive system for the hydrorotors;

FIG. 7 is a view of the rotor drive system taken on line 77 of FIG. 6 and shown partially in cross-section;

FIGS. 8 and 9 show another embodiment of the hydrorotor drive system which incorporates a retractable tilted wheel for land operation;

FIGS. 10A, 10B and 10C are schematic side views of hydrorotor embodiments;

FIGS. 11A and 11B are schematic plan views of blade and rotor-center configurations of the hydrorotor;

FIG. 12 is a view partially in cross-section of a control system for a hydrorotor embodiment having movable flaps;

FIG. 13 is a plan view of a portion of the variable flap type hydrorotor and taken on line 1313 of FIG. 12;

FIG. 14 is a view taken on line 14-44 of FIG. 13 and showing a configuration of the hydrorotor blades with movable flap;

FIG. 15 is another schematic plan view of a craft incorporating the invention and utilizing a submerged hydrofoil and directional control rudders;

FIG. 16 is another embodiment of the invention incorporating a single hydrorotor;

FIG. 17 is an embodiment of the hydrorotor drive mechanism positioned within the hull of the craft;

FIG. 18 schematically shows the surface contact area of a pair of hydrorotors in diflferent maneuvering positions and control mechanism therefor;

FIG. 19 is a side view of the FIG. 18 control wheel with different control positions being shown in dash lines; and

FIG. 20 shows a control wheel and associated mechanism for controlling a hydrorotor craft.

Basically the invention relates to craft propelled by at least one hydrorotor. One embodiment employs pairs of contra-rotating rotors located in planes nearly parallel to the water surface to obtain lift and inclined outwardly from the longitudinal axis of the craft to obtain thrust. Maneuvering is accomplished by rotating the tilt axes of the hydrorotors thereby changing the direction of reaction against the water to change the direction of thrust. Another embodiment employs pairs of hydrorotors for waterborne support and propulsion with pneumatic-tired wheels mounted on shafts concentric with the hydrorotor shafts which, when operating on water, are retracted so as not to interfere with the hydrorotors and, when operating on land, are extended below the hydrorotors whereby the hydrorotors do not interfere with land operation. An other embodiment employs a hydrorotor driven by an inboard or outboard motor and forward-mounted on a craft for partial support and for propulsion and steering thereof.

A hydrorotor craft is a powered boat or marine vehicle in which the hull or other buoyant supporting means is lifted clear of the water during normal operation of the vehicle by one or more hydrorotors, which also furnish the thrust to propel the vehicle.

A hydrorotor is a multi-bladed axial-screw rotor somewhat similar to a helicopter rotor, but designed to operate close under or at the surface of the water. The plane of the rotor disk is tilted on the order of ten to twenty degrees from the horizontal. The rotor blades may also be spanwise tipped up to the same ten to twenty degree angle, making the solid shape enclosed by the blades a shallow cone rather than a disk.

Hydrorotors operate submerged during low-rotor-speed maneuvering of the vehicle and during liftout, but their prime and most eflicient operating mode is with most of the rotor in air above the water, with approximately one quarter of the blades contacting and planing on the surface of the water or slightly piercing the water on one side of the rotor only, as a result of the rotor tilt. The few planing blades of an operating hydrorotor are moving in essentially the same direction with respect to each other, therefore the input torque to the rotor is transformed into a unilateral thrust.

The thrust from each of the rotors, in normal straightahead operation, is forward. The thrust is the hydrodynamic drag of the blades, but since the working blades are moving aft instead of forward, as is the case with conventional hydrofoils, hydrorotor blade drag is not vehicle drag, but vehicle thrust. Since no part of the vehicle except the working blades of the rotors is in contact with the water, there is no vehicle hydrodynamic drag. Since vehicle hydrodynamic drag or resistance is eliminated, the only remaining resistance is aerodynamic drag. The hydrodynamic drag on a racing hydroplane, for example, is about three times the aerodynamic drag. Therefore, hydrorotor craft are capable of much higher speeds for a given power and weight than hydrofoil or planing boats. Likewise due to the high lift and propulsion efiiciencies, hydrorotor craft are theoretically faster than ground-effect craft.

Hydrorotor craft may be steered or maneuvered in any direction in a manner similar to the helicopter, either at low speed while buoyantly supported, or at high speed with the hull out of water, by tilting the rotors in different directions. In the case of the hydrorotor craft, the tilt angle is always constant, but the direction of tilt of the rotor is changed. This mutation of the rotor tilt axis is used to direct the thrust component of submerged rotors or the thrust resulting from aft-moving blade drag of planing rotors in any desired direction. By proper combination of the nutation angles of the several rotors of the craft, it can be made to turn, spin on its own axis, hover, go forward or astern, or sideways at low speed with the hull in, or dynamically supported with the hull out of water.

The sum of the lift forces on the several rotors of a planing hydrorotor craft must equal the gross weight of the craft. As with other dynamic-lift vehicles, the lift is proportional to velocity squared and to working area.

When a hydrorotor craft is hovering with no forward velocity the velocity appearing in the lift equation is the mean velocity of the rotor blades due to their rotation. When the craft acquires velocity, however, the rotor rotational velocity must increase by the amount of the craft velocity, so that the slip velocity, or relative velocity of the blades to the water remains the same as when the vehicle was hovering. The slip velocity alone produces the lift and thrust. If the slip velocity decreases slightly, the rotor will sink deeper in the water and the working blade area will increase to maintain the same lift. If the slip velocity decreases too much, so that the reserve working area of the rotor is used up, the rotor lift will be less than the lift required and the craft will settle down into partial buoyant-hull support.

If the rotor slip velocity increases, the rotor will rise up further and reduce its working area keeping the total lift equal to the Weight on the craft. Unnecessarily high slip velocity will result in inefiicient operation since theoretical hydrorotor propulsion elficiency is vehicle velocity vehicle velocity-l-slip velocity The propulsion efiiciency on hydrorotor craft and similar aft-moving-dynamic-foil vehicles increases with increasing vehicle velocity at constant lift to drag ratio (L/D) and can reach values on the order of eighty percent at reasonable vehicle-velocity to slip-velocity ratios. High speed planing boats and hydrofoil boats, on the other hand, normally use super-cavitating screw propellers which are notably inefficient, and get worse as the velocity increases.

Not only is the higher propulsion elficiency of hydrorotor-.ype vehicles significant, but doubly significant is the fact that hydrorotor-type vehicles only require on the order of one quarter as much propulsion thrust as hydrofoil boats, because the former have no hydrodynamic drag, only hydrodynamic thrust balancing aerodynamic drag.

To avoid all hydrodynamic drag or resistance on a hydrorotor craft, it is necessary that all blades or portions of blades in contact with the water have a positive slip velocity or relative velocity aft with respect to the water. Then blade drag will be vehicle thrust. Any contacting blade portions moving forward with respect to the water produces vehicle hydrodynamic drag. The slip velocity on the working blades of a planing hydrorotor decreases from the outer tips or rotor periphery inward. If the blades are not terminated at some critical inner radius, the slip velocity goes negative at the inner end, near the rotor hub, and introduces vehicle drag.

In order to keep the slip velocity of the inner ends of the blades from going negative, the

rotor blade length rotor radius ratio must never be more than the maximum slip velocity slip velocity-l-vehicle velocity ratio. Thus, if low design slip velocities are chosen in order to keep theoretical propulsion efficiency high, the working length of the rotor blades must be short with respect to the rotor diameter.

Hydrorotor craft efliciently utilize fixed rotor blade incidence or angle of attack. However, for very high vehicle velocities, variable blade angle flaps, or other thrust augmentation means are employed.

For hovering or low-velocity maneuvering, the thrust requirement is nil or very low, so for high efliciency the rotors operate at the highest possible L/D, which will occur at a low blade angle of attack. At all moderate velocities the thrust available as a by product of the lift, with maximum lift-to-drag-ratio rotors, will exceed the thrust required.

As the velocity of the craft increases the thrust requirement increases as the square of the velocity since the thrust must balance aerodynamic drag. The lift required must remain constant since the gross weight is fixed. The rotors will provide thrust enough to achieve a certain high velocity at maximum rotor L/D but beyond that velocity the L/D of the rotors has to decrease to furnish more thrust at the same lift value. This obviously also requires more rotor torque. Increasing prime mover speed so as to increase the slip velocity of the rotors has little or no efiect on vehicle velocity since L/ D is essentially independent of velocity at constant angle of attack and the higher engine speed would only increase the fuel consumption.

In order to decrease the L/D to get the required thrust for very high vehicle speeds (in the order of 200 knots and above) the following may be utilized:

1) The angle of attack (angle of incidence) of the rotor blades can be increased.

(2) The aspect ratio of the blades can be decreased.

(3) Auxiliary flaps or paddles can be utilized. The latter approach is preferable and will be described in greater detail hereinafter.

Over most of the vehicle velocity range (up to approximately 200 knots) the rotors operating at attainable liftto-drag ratios will provide excess thrust over that required to overcome aerodynamic drag and the minor hydrodynamic drag due to spanwise flow on the rotor blades at high contact angles. Therefore, higher maximum L/Ds are desirable in order to reduce horsepower required and fuel consumption at medium and low velocities.

For constant velocity it is necessary that total drag and total thrust balance. If excess thrust exists the vehicle will accelerate. If the rotor r.p.m. is not allowed to increase to keep pace with the higher vehicle velocity, the slip velocity will decrease. In order to maintain lift the working blade area has to increase, increasing the rotor contact angle, decreasing the thrust efliciency, and increasing the hydrodynamic drag due to spanwise components of blade flow due to the higher contact angle. These effects will bring about a stable balance between thrust and drag and a stable velocity for any given throttle setting. If needed, hydrodynamic drag could be purposely introduced by putting down a hydrodynamic drag brake to balance the thrust.

Nutation of opposing rotors in such a way as to cancel out the excess thrust over drag at any velocity can be utilized. The nutation must be in the direction to move the working area of the rotor aft so that the aft blades act as hydrodynamic drag brakes in addition to supply lift.

Some angle of tilt must be used on a hydrorotor to get horizontal thrust either during submerged running or during planing operation. During submerged rotor operation, the thrust is the rotor axial force times the sine of the tilt angle, while the lift is the axial force times the cosine of the tilt angle. During planing operation, the tilt angle allows the rotor to plane on a few blades on the low side of the rotor, while the other blades and all of the rotor structure is clear out of the water, thus the thrust is the drag of the planing blades in contact with the water and the lift is the lift force of the planing blades.

If the rotor is built cone shaped with the cone angle the same as the rotor shaft tilt angle, then the blades on the low side of the rotor will lay flat on the water during planing and the lift of these working blades will be vertical. Increasing the rotor shaft tilt angle and the cone angle equally results in greater clearance of the non-working blades above the water for a given rotor diameter, thus improving the rough water performance of the vehicle. Excessive tilt and cone angles, however, reduces the effective radius of the circular path of blades entering and leaving the surface of the water, thereby reducing the number of blades working. This reduced path radius also results in deeper immersion of the planing blades in order to get enough working area to support the load which results in a higher effective angle of attack on entering blades.

If the cone angle is zero or less than the shaft angle the outer tips will pierce the water slightly more than the inner tips, or as the slip velocity increases, less area will be required to support the craft and the inner ends of the blades will rise free of the water (even on the working side of the rotor). This will allow the craft velocity to go up without the slip velocity of the innermost part of the blades which are contacting the water from approaching zero or going negative. This configuration of rotor functions similar to fixed surfacepiercing hydrofoils with respect to automatic adjustment of working area.

Hydrorotor craft, like planing and hydrofoil boats,

will have problems due to waves, floating debris, and shallowly submerged objects. The higher the operating speed, the more serious these problems become. However, due to the unique method of operation of the hydrorotor craft, small waves and debris is not as serious a detriment as they are to hydroplane or hydrofoil boat operation because of the low velocity of the planing hydrorotor blades with respect to the water. The blade slip velocity remains low and essentially constant, regardless of vehicle velocity, so the blades hit the waves or debris at a relatively low velocity with respect to the crafts velocity. Furthermore, the working blades hit oncoming waves or debris as the blades are moving aft with respect to the water and thus strike them on the side opposite to that which a hydrofoil boat would hit them.

Since the hydrorotor craft is plan ng in normal operation and has no submerged hydrofoils, propellers, rudders, etc., they can run safely over slightly submerged dead heads, sand bars, rocks, etc., Without damage thereto. In addition, the craft could plane over marsh grass or seaweed areas or in cases of emergency could run onto sandy beaches with little or no damage.

Waves high enough to strike the returning or airborne rotor blades during high speed operation could be dangerous to the rotor structure, as well as produce violent shocks in the craft, since these blades will have a relative velocity with respect to the water of over twice the vehicle velocity. Thus shielding the forward moving blades from these waves or breaking up of the waves by positioning a rigid wave-splitter post at the bow of the craft is necessary. The latter approach will be described in greater detail hereinafter.

Referring now to specific embodiments of the invention as shown in the drawings, the hydrorotor craft, for ex ample, a ferry boat, shown in FIG. 1 includes a hull 1 having a wave-splitter post 2 of triangular cross-section extending down from the hull forward from and between the forward pair of rotors 3, but stopping short of the planing surface. Wave-splitter 2 splits oncoming waves much as a sharp bow splits the water and deflects the waves away from the forward moving blades of rotors 3, without introducing appreciable vertical or lateral forces on the craft. Waves passing over the aft-moving blades of rotors 3 are of relatively little consequence, since the relative velocity of these aft-moving blades is low and they are already in contact with the water on their lower surfaces.

Referring now to FIGS. 2 and 3 which show a hydrorotor craft 11 provided with a wave-splitter 12 which deflects the oncoming waves as indicated by the arrows, and propelled by four (4) rotors 13, both left hand rotors turning counter-clockwise and both right hand rotors turning clockwise when viewed from above as indicated by the arrows in FIG. 2. The forward rotors 13 are shown in FIG. 2 to illustrate blade configuration while the rearward rotors show at 14 the approximate contact or working area between rotors 13 and the surface of water 16. Rotors 13 are cone shaped and mounted on tilted shaft means 15 as shown in FIG. 3.

Craft 11 is supported on the surface of the water by dynamic action of rotors l3 and the drag of the blades of the rotors which are moving aft on the water provides thrust for accelerationand high-speed operation. Rotors 13 turn in a plane nearly parallel with the surface of the water 16 as shown in FIG. 3. Rotors 13 are similar to the rotor(s) of a helicopter but are designated to generate lift and thrust under the water, and lift and thrust on the surface of the water. As the blades of rotors 13 come to the surface, their action will change from submerged hydrofoil action to lower surface planing.

To obtain thrust to propel craft 111 the axes of rotor shafts 15 are tilted outward from the longitudinal centerline of the craft, as shown in FIG. 3, whereby the blades engage the surface of the water only on the outboard and rearward moving part of their cycles. Therefore, the drag of the blades on the water in this limited area of contact results in thrust for the craft with substantially no drag or resistance due to the craft moving through the water since only the backward moving blades of the rotors contact the water and the craft is supported above the water.

Rotors 13 are conical to prevent the tips of the outboard or backward moving blades from deeply piercing the water, thus reducing the resultant losses and helping to insure that the inboard or forward moving blades do not contact the water. The cone angle of the blades of rotors 13 is essentially the same as the tilt angle of rotor shaft 15 so the outboard or rearward moving blades are nearly parallel with the water and the inboard or forwardmoving blades are sweeping up at twice the shaft angle. The hubs of rotors 13 are recessed in any known manner so that they will not drag in the water.

While the bottom of craft 11 is shown in FIG. 3 as having an inverted V configuration, any other configuration may be utilized that is compatible with engineering requirements, catamaran hulls having especial merit on hydrorotor craft.

Hydrorotors 13 are utilized to maneuver craft 11 during dynamically supported operation, as shown in FIGS. 4A-4C, and during buoyant-supported low-speed operation, as shown in FIGS. SA-SD.

During dynamically supported operation the direction of movement of craft 11 is controlled by changing the direction in which the working area 14 of rotors 13 contacts the water. In the forward operation (FIG. 4A), working areas 14 of all rotors 13 contact the water on their outboard and rearward moving part of the cycle. As shown in FIG. 413, a right turn is made by rotating working area 14 of the two forward rotors 13 to the right 90 thus shifting their thrust vector while the two rearward rotors remain in the forward-thrusting position. FIG. 4C shows the position of rotor working areas 14 for reverse movement of craft 11 wherein each working area is rotated 180 from their forward operation positions. Mechanism for changing the contact direction of rotor working areas 14 is shown and described in detail hereinafter.

While not shown, the thrust vectors of all rotors 13 can be shifted 90 from their forward position, thereby producing only lateral thrust for moving craft 11 sidewise, or to a position which cancels out thrust whereby the craft will hover.

During buoyant-support low-speed operation the direction of movement of craft 11 is controlled by the same mechanism as in dynamically supported operation but rotors 13 are submerged. As shown in FIG. A, for forward operation rotors 13 have their lower edges forward, centered under the axes of drive shafts 17 to be described hereinafter, so that the forward thrust is the rotor axial dynamic force multiplied by the sine of the tilt angle. For reverse operation rotors 13 are positioned with their lower edges again centered under the axes of shaft 17 but with their upper edges 180 from the forward position about the axes of shafts 17, as shown in FIG. 5B. For docking or lateral movement of craft 11, as shown in FIG. 5C, the upper edges of rotors 13 are positioned 90 from the forward position about shafts 17. FIG. 5D shows the positions of the upper edges of rotors 13 with respect to shafts 17 for a left turn in place wherein the forward rotors are positioned 90 to the right of shafts 17 while the rearward rotors are positioned 90 to the left of shafts 17 with respect to their forward position.

It is thus clearly shown that during all operating conditions of the craft (dynamically-supported or buoyantlysupported) the lower edges of rotors 13 are always centered under the axes of drive shaft 17 which is positioned vertically with respect to the surface of smooth water.

Referring now to FIGS. 6 and 7, the hydrorotor drive system comprises a prime mover 18 such as an internal combustion engine or gas turbine unit, drive shafts 19 interconnecting prime mover 18 and gearing units 21),

gearing units 20 being connected to rotor drive shafts 17 via shaft and gearing mechanism 21. A clutch 22 is provided between each rotor drive shaft 17 and its respective gearing unit 20.

As shown in FIG. 7, a hollow housing 23 is mounted on the bottom hull of craft 11 by attaching means such as bolts 24. A hollow housing 25 is rotatably mounted in housing 23 on bearings 26. Rotor drive shaft 17 extends downward into housing 25 and is connected to rotor 13 via drive gears generally indicated at 27 and tilted rotor shaft 15, shafts 15 and 17 being mounted in housing 25 on antifriction type bearing means. A servo motor 23 is mounted on housing 23 and drivingly connected with housing 25 via gears 29 and 31) which rotate housing 25 and rotor 13 with respect to drive shaft 17 to provide thrust directional control as described above for maneuvering craft 11. Servo motor 28 is operatively connected to control unit 31 (see FIG. 6) and driven in conventional manner from prime mover 18.

While the drive system has been specifically described as employing a single prime mover, each rotor drive shaft 17 may be driven by an individual prime mover, such as a gas turbine engine or an electric motor if desired. Furthermore, in applications where the forward rotors are of different diameter than the rearward rotors, drive systems between the prime mover and rotor drive shafts may be utilized to drive the individual rotors at different speeds by the same prime mover, in order to drive all of the rotors at the same slip velocity.

FIGS. 8 and 9 show an embodiment of the invention in an amphibious craft equipped with both hydrorotors and pneumatic wheels mounted concentrically whereby the pneumatic wheels may be lowered for land operation. As shown in FIG. 8, a hollow housing 23 is attached to the hull bottom of an amphibious craft 11 by bolts 24, hollow housing 25 is rotatably mounted within housing 23 on bearings 26 and rotatably controlled by servo motor 28 through gears 29 and 30 as in the FIG. 7 embodiment. As in the FIG. 7 embodiment, hydrorotor 13 is drivingly connected with a prime mover via drive gear mechanism 21, rotor drive shaft 17, drive gears 27 and tilted rotor shaft 15', said rotor shaft 15 being hollow. The hub of hydrorotor 13' is contoured so as to house a wheel 32 having a pneumatic tire tread 32'. During water-borne operation, wheel 32 is positioned in the hub 33 of rotor 13' so as not to interfere with the operation of the rotor.

Wheel 32 is connected to a shaft 34 which extends through hollow rotor shaft 15'. Mounted on shaft 34 is a piston 35 which cooperates with the interior of shaft 15 to define a double acting hydraulic cylinder having working chambers 36 and 37. Sealing means such as O-rings 33 are positioned around shaft 34 at the ends of chambers 36 and 37 and between piston 35 and the interior of shaft 15. The lower side of piston 35 is provided with a plurality of teeth 39 which are designed to mate with teeth 40 mounted on closure member 41 of shaft 15', said closure member 41 being drivingly connected with rotor hub 33. Upon actuation of a control valve (not shown) pressure fluid is directed from a source (not shown) through conduit 42, passageway 43 in shaft 34 to chamber 36, chamber 37 being connected through passageway 4-4, conduit 45 to a low pressure reservoir (not shown), whereby pressure fluid in chamber 36 forces piston 35, shaft 34 and wheel 32 downwardly and engage teeth 39 and 4-0 which cause wheel 32 to rotate with rotor 13'. The position of wheel 32 and piston 35 for land operation is shown in dash lines in FIG. 8. To retract wheel 32 for water-borne operation the fluid pressure is released from chamber 36 and directed to chamber 37 by the control valve whereby piston 35, shaft 34 and wheel 32 move upwardly disengaging teeth 39 and 40.

While a double acting hydraulic actuator has been de scribed, a single acting unit may be utilized wherein the piston 35 will be returned by a spring means or other conventional mechanism.

While a hydraulic actuator for controlling wheel 32 has been described, mechanical, electrical or pneumatic actuation may be utilized. Furthermore, wheel 32 may be continuously driven with rotor 13' by the implementation of well known mechanical drive mechanisms.

FIGS. 1OA-1OC schematically show embodiments of hydrorotor configuration wherein FIG. A is a cone type planing rotor having a flat closed or spoked center 50 with tilted blades 51. FIG. 10B is a cone type planing rotor having an inverted gull wing or V-center configuration for better wave clearance at the center disk or spokes 50 with blades 51 being tilted to the desired angle. FIG. 10C is a surface-piercing rotor 52 for upper-blade surface lifting by penetration of the water surface, having no cone angle and may utilize either a flat center disk or spokes.

FIG. 11A schematically shows a rotor configuration utilizing a disk or wheel type center 53 with blades 54 while FIG. 11B schematically shows a rotor configuration employing a bladed-spoke type center 55 for fast rise-out and peripheral blades 56.

The blade cross-section, blade aspect ratio, blade plan form, and number of blades on the hydrorotors will be determined by the specific application of the rotors and design requirements thereof. However, it is preferred that the blades be of the subcavitating foil-type. It is noted that hydrorotors can always operate subcavitating even at very high vehicle speeds, since the effective blade velocity is only the low slip velocity.

As set forth above, variable blade angle or other thrust augmentation is required for hydrorotor operation at very high craft velocities only. FIGS. 12-14 show an embodiment of auxiliary rotor blade flaps for high speed use and control mechanism therefor.

As shown in FIG. 12, the hull bottom of a hydrorotor craft 11 is provided with housing 23, a rotatable housing 25 having rotor drive shaft 17', drive gears 27 tilted rotor shaft rotatably mounted therein and drivingly interconnecting drive mechanism 21 with hydrorotor 13". Mechanism for rotating housing 25 for steering the craft is the same as that described above and shown in FIG. 7. Shafts 15" and 17' and each of gears 60 and 61 of gear drive 27, are hollow. A control shaft 62 extends through rotor drive shaft 17 and gear 60 and is connected to one end of a bell crank 63 pivotally mounted at 64. The other end of crank 63 is operatively connected through a pin and slot type lost motion device 65 to one end of another bell crank 66 pivotally mounted at 67. The other end of crank 66 is connected to one end of a shaft 68 which extends through gear 61 and shaft 15". Shaft 15" is operatively connected at the end opposite crank 66 to two (2) bell cranks 69 which are pivotally mounted at 70. The other end of each bell crank 69 is operatively connected with blade flap control ring 71, said ring 71 being connected to blade flaps 72 through flap horns 73 (see FIGS. 13 and 14). Blade flaps 72 are positioned behind rotor blades 74, said blades 74 being connected to hub 75 or rotor 13".

In operation, the raising or lowering of control shaft 62 by actuating mechanism (not shown) pivots bell crank 63 about pivot 64 which causes bell crank 66 to pivot about point 67 which moves shaft 68 and pivots bell cranks 69 about point 70 which in turn rotates control ring 71 for raising or lowering the trailing edge of blade flaps 72 thereby changing the thrust characteristics of rotor 13".

While blade flaps 72 have been shown as being pivotally mounted at the trailing edge of rotor blades 74, the flaps 72 can be mounted separately from blades 74, if desired.

As pointed out above, the angle of attack of the rotor blades can be changed by mechanism (not shown) to modify the left over drag ratio (L/D) to obtain the desired thrust. This feature may be utilized separately 1Q or in combination with the auxiliary flaps described in FIGS. 1214.

The cone angle of the rotors (angle of the blades with respect to the tilt angle of the rotor shaft) may be made variable by mechanism within the skill of the art, thus variation of the rotor blade angle may be utilized to change the performance of the rotors, if desired.

The embodiment of the hydrorotor craft shown in FIG. 15 includes catamaran hull 80, a wave splitter or deflector 81 mounted at the bow of the hull inner structure and extending downward to near the surface of the water. Two pairs of rotors 82 are mounted on drive shaft means for lifting and propelling the craft over the surface of the water. The forward pair of rotors is nutatable by means similar to the embodiment shown hereinafter in FIG. 17. The rear rotors have their tilt axes fixed in the forward-planing orientation for simplicity. Each of rotors 82 have a contact or working blade area 83. As viewed from above, the left forward rotor and the right rearward rotor rotate in a counter clockwise direction while the right forward rotor and left rearward rotor rotate in a clockwise direction, whereby the action of the forward rotors 82 do not disturb the water at the contact area of the rearward rotors 82. A hydrofoil 84 is mounted on struts 85 between the forward and rearward pairs of rotors 82, said hydrofoil 84 functioning to provide part of the lift to support the craft at planing speeds. Mounted at the stern of hull 81) are two (2) steering rudders 86 which are controlled in conventional manner to assist in steering the craft. Rotors 82 are driven individually or in combination by any desired type of prime mover in the manner described above and shown in FIG. 6 or in any well known manner.

FIG. 16 is an embodiment of a water craft, such as a racing boat, which is powered by and partially sup ported by a hydrorotor while the remaining weight of such craft is supported by a planing surface. The craft includes a hull 90 having a hydrorotor 91 mounted at the bow of hull 91), said rotor 91 and the drive mechanism therefor is similar to that shown in FIG. 7 except that prime mover 92 may be of the outboard type which is removably clamped to the hull 90 by conventional means (not shown). The hydrorotor 91 is designed to be rotated 360 about its vertical drive shaft 93 for steering and reversing in addition to forward propulsion, either on the surface While dynamically supported, or with the hydrorotor submerged while the hull 90 is buoyantly supported at low speeds. The stern of bull 90 is supported during dynamically supported operation of rotor 91 on a planing contact area 94.

As shown in FIG. 16, the craft is in a turn to the right as indicated by arrow 95, the contact area of rotor 91 is shown at 96 while 97 indicates the portion of the rotor cycle that is in the air. Dashed circle 98 indicates the movement of the hub of rotor 91 about drive shaft 93 during maneuvering of the craft, while arrow 99 indi cates the direction of thrust.

While the craft shown in FIG. 16 employs a planing surface for the stern of hull 90, it could be supported by hydrofoils, if desired. Furthermore, two hydrorotors may be utilized for propulsion and maneuvering instead of a single unit as shown, or the prime mover 92 may be of the inboard type.

While the hydrorotor has been shown in FIG. 16 on the bow of hull 99, it can be mounted at the stern with appropriate mechanism for supporting the bow, such as hydrofoils, and for holding the bow into the turn during maneuvering, such as a midship or forward fin, keel or other lateral area piercing the water.

The internally mounted drive mechanism as shown in FIG. 17 comprises a water craft 111 having a hydrorotor 113 operatively positioned in the bottom of the hull on a shaft 115 which is tilted with respect to the vertical and to the water surface 116. A hollow housing 123 is attached to the hull bottom by any suitable means (not shown). A hollow housing 125 is rotatably mounted in housing 123 on bearings 126. A vertical drive shaft 117 for rotor 113 extends into the upper end of housing 125 and is drivingly connected with rotor 113 through rotor shaft 115 and gearing means 127, shafts 115 and 117 and gearing means 127 are rotatably mounted in housing 125 on appropriate bearing means. Rotor drive shaft 117 is connected to a prime mover through drive mechanism 121. Housing 125 is rotated about the axis of shaft 117 through drive means 130 for steering of craft 111. The drive mechanism and steering mechanism for the FIG. 17 embodiment may be of the type described above with respect to FIGS. 6 and 7. To prevent leakage of water into housing 125, seals 129 are provided between shaft 115 and housing 125 and between housing 123 and housing 125. As in each of the embodiments described above the center of lift of rotor 113 is directly under the axis of shaft 117 as indicated by the centerline 130 regardless of the position of rotor 113 as its axis is moved about shaft 117 during all operating conditions.

The FIG. 17 embodiment has the advantages of: (1) reduced aerodynamic drag, (2) reduced hydrodynamic drag due to waves and during low-speed submerged-rotor maneuvering, and (3) eliminates the possibility of water entering the gearing housing while permitting nutation control of the rotor for steering by positioning the center of lift and thrust of the hydrorotor directly over the nutation bearings 126 and rotor drive shaft 117, no net torque from the drive of an opposing pair of rotors is reflected back through the steering system, and support points for the craft do not move during maneuvering.

FIGS. 18 and 19 show a hydrorotor craft 131 having a Wave-splitter 132 and four rotors, 133A, 133B, 133C and 133D for lifting and propelling the craft, ro-tor rotation being in the same direction as in FIG. as indicated by the arrows on each rotor. The forward pair of rotors 133A and 13313 are adapted to be rotated by pulleys 133 and 133', respectively, about the drive axis for steering of the craft as in the above embodiments while the rearward pair of rotors 133C and 133D are of the fixed type having a contact or working area 134 that remains in the same orientation with respect to the drive axis during all operating conditions.

The forward pair of rotors 133A and 133B are each shown schematically for purpose of illustration as having four (4) separate quadrants showing the location of the lower portion (planing working area) of the rotor with respect to craft 131 for different operating conditions of the craft for both buoyant-support (submerged) and dynamic-support (planing) conditions. Looking at rotors 133A and 133B from above, the lower blade positions of each of said rotors is in quadrant I during submerged forward operation and in quadrant III during submerged astern operation. During submerged right turn operation rotor 133A is in quadrant II and rotor 133B is in quadrant 1V while rotor 1333A is in quadrant IV and rotor 133B is in quadrant II during submerged left turn operation. During planing forward operation rotors 133A and 133B are in quadrant II. During planing left turn operation rotor 133A is in quadrant I and rotor 1338 is in quadrant III while rotor 133A is in quadrant III and 133B is in quadrant I during planing right turn operation. During /2 speed planing forward operation the working area of rotors 133A and 13313 are in quadrant III. During planing hover operation rotors 133A and 133B are in quadrant IV which gives hover on the entire craft because the aft thrust from quadrant IV forward rotors is cancelled by the fixed forward thrusting rear rotors 133C and 133D.

The thrust orientation of rotors 133A and 133B is controlled by a cable-drum system schematically shown in FIGS. 18 and 19 and including a control wheel 135 mounted on a control column 136; column 136 and wheel 135 being operatively connected to drums 137 and 138 through shaft and gearing means generally indicated at 139 and operatively mounted on support members 140. A cable 141 extends around control pulley 133 attached to gear housing of rotor 133A, directional change pulleys 142 and drum 137 while cable 143 extends around control pulley 133' attached to gear housing of rotor 133B, directional change pulleys 144 and drum 138.

The arrows in FIGS. 18 and 19 on cables 141, 143 and control wheel 135 indicate the direction of motion required to start craft 131 into a left turn to show that turning of control wheel 135 causes craft 131 to be steered in accordance therewith.

As shown in FIG. 19, the position of control column 136 with respect to its vertical position determines the quadrant in which the planing blade working area or the lower side of the rotors is located. Since the normal operating direction is forward, column 136 when in its vertical position II, as shown in solid lines, positions the blade working areas of rotors 133A and 133B in quadrant II. Movement of control column 136 fore and aft from the vertical position II as shown by dash lines and indicated by positions I, III and IV in FIG. 19 causes the working areas of rotors 133A and 133B to be positioned in corresponding quadrants I, III and IV shown in FIG. 18.

When column 136 moves fore or aft, drums 137 and 138 move with it thus changing the quadrant in which the blade working area of rotors 133A and 133B function. One embodiment of the mechanism for accomplishing control of the rotor quadrants is shown in FIG. 20. The degree of swing of column 136 and turn of wheel 135 will depend on the specific design of the gears, drums and pulleys utilized and the diameter of the rotors. However, 45 to total swing on control column 136 should rotate the axis of rotors 133A and 1333 270 about the drive axis thereby providing full maneuvering ability.

Referring now to FIG. 20 which shows in detail an embodiment of the control mechanism shown in FIGS. 18 and 19 as viewed from the stern of craft 131. Control wheel is operatively mounted at one end of control column 136, the opposite end of column 136 being operatively connected with gear mechanism 139 described in detail hereinafter. A shaft 145 is rotatably mounted in column 136 and connected with wheel 135 through gearing 146. Gear mechanism 139 comprises a shaft 147 rotatably supported in fixed structure 140, composite spur and bevel gears 148 and 149 mounted free to rotate on shaft 147, the bevel portions of said composite gears 148 and 149 being connected to shaft 145 through bevel gear 150. The lower end of column 136 terminates in a U-shaped configuration wherein legs 136 of column 136 are rotatably mounted on shaft 147. Spur portions of composite gears 148 and 149 mesh with pinions 151 and 152, respectively, said pinions 151 and 152 being fixedly attached to cable drums 137 and 138 and rotatably mounted on shaft 153 and support structure 1411. Cables 141 and 143 are wrapped on drums 137 and 138, respectively, and are connected to control means of rotors 133A and 133B as shown in FIGS. 18 and 19.

The general operation of the FIG. 20 mechanism having been set forth above with respect to the description of FIGS. 18 and 19, a specific description thereof is deemed unnecessary in that the operation can be clearly followed through movement of column 136 fore and aft about shaft 147 which rotates drums 137 and 138 in the same direction, and through turning of wheel 135 which rotates drums 137 and 138 in opposite directions through gear mechanism 139.

While the control system has been shown in FIGS. 18-20 as a manually actuated gear and cable system, an

- 13 electric, hydraulic or pneumatic system may be employed to position the working blade areas of rotors 133A and 133B in their proper maneuvering quadrants I through 1V.

It has thus been shown that the instant invention provides a new concept in propulsion, support and maneuver systems for water and/or land craft and provides high speed water-borne operation well over the speed of water craft employing present known propulsion, support and maneuver systems.

Although particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention, and it is intended to cover in the appended claims all such changes and modifications that come within the true spirit and scope of the invention.

What I claim is:

1. Propelling and supporting means for a water craft including at least one rotor having a hub portion and a plurality of blade-like members extending from said hub portion and at an angle thereto, driving means for said rotor, said rotor having an axis positioned at an angle with respect to the axis of said driving means, and means for rotating the rotor axis about the axis of said driving means, whereby less than one-half of said blade-like members are in contact with the water during planing operation of the craft.

2. The propelling means defined in claim 1 including flap-like members operatively positioned at the trailing edge of said blade-like members, and means for moving said flap-like members with respect to said blade-like members.

3. Propelling and supporting means for a water craft including at least one rotor means, said rotor means comprising a hub portion, a shaft positioned in said hub portion, and a plurality of blade-like members extending from said hub portion at a predetermined angle, whereby during planing operation of the craft less than onehalf of said blade-like members are in contact with the water and at an angle substantially parallel to the surface thereof.

4. The propelling means defined in claim 3 including flap-like members operatively positioned at the trailing edge of said blade-like members, and means for moving said flap-like members with respect to said blade-like members.

5. The propelling means defined in claim 3 wherein said hub portion is a flat disk, and said blade-like members have a substantially flat lower surface.

6. The propelling means defined in claim 3 wherein said hub portion is of an inverted V cross-section configuration, and said blade-like members having a substantially flat lower surface.

7. The propelling means defined in claim 3 wherein said hub portion comprises ring members and a plurality of spokes extending between said ring members, and said blade-like members having a substantially flat lower surface.

8. Support, propulsion, and maneuvering means for a water craft including a plurality of rotor means, each having a hub portion and blade-like members extending from said hub portion at an angle thereto, said rotor means each having an axis extending at an angle with respect to a vertical support axis of said rotor means, said blade-like members having a longitudinal axis extending at an angle with respect to the axis of said rotor means, driving means for said rotor means for supporting and propelling said craft, and means for rotating the axis of at least one of said rotor means about said vertical support axis of said rotor means for maneuvering said craft, whereby a portion of said blade-like members move substantially parallel to the water surface during planing operation of the craft.

9. The device defined in claim 8 including flap-like members operatively positioned at the trailing edge of said blade-like members, and means for moving said flaplike members with respect to said blade-like members.

10. Propelling and supporting means for an amphibious craft including a plurality of rotor means, each of said rotor means having a hub portion and a plurality of blade-like members extending from said hub portion, a wheel-like means positioned in said rotor hub portion, means for extending or retracting said wheel-like means with respect to said rotor hub portion, and means for driving said rotor means, said driving means including means for driving said wheel-like means.

11. A water craft including at least two pair of rotor means for propelling and at least partially supporting said craft, each of said rotor means having a hub portion and a plurality of blade-like members extending from said hub portion at an angle thereto, means for driving said rotor means, one rotor means of each of said pairs of rotor means being rotated by said driving means in a direction opposite to the direction of rotation of the other rotor means of each of said pairs of rotor means, means for maneuvering said craft, and wave deflecting means mounted on craft.

12. The water craft defined in claim 11 wherein said means for maneuvering said craft includes rudder means.

13. The water craft defined in claim 11 wherein said means for maneuvering said craft includes means for moving at least one pair of said rotor means with respect to a vertical support axis of said rotor means.

14. The water craft defined in claim 11 including flaplike members operatively positioned at the trailing edge of said blade-like members of said rotor means, and means for moving said flap-like members with respect to said blade-like members.

15. Propelling and supporting means for a water craft including at least one rotor means having a hub portion and a plurality of blade-like members extending from said hub portion and at an angle thereto, said rotor means having an axis extending at an angle with respect to a vertical support axis of said rotor means, and means for rotating said rotor means, whereby a portion of said blade-like members move substantially parallel to the surface of the water during rotation of said rotor means thus producing lift and linear reaction thrust on the sur face of the water during planing operation and lift and thrust under the water surface during buoyant supported operation.

16. In a water craft, means for simultaneously propelling and dynamically supporting the craft during planing operation which additionally functions to propel the craft during buoyant supported operation consisting of a plurality of rotor members mounted on shafts which are tilted with respect to the vertical, each of said rotor members including a plurality of blades mounted at an angle to said tilted shafts, means for rotating said rotor members whereby a portion of said blades move substantially parallel to the surface of the water during rotation of said rotor members thus producing lift and linear reaction thrust on the surface of water during planing operation and lift and thrust under the water surface during buoyant supported operation, said rotor members rotating in a direction to move said portion of said blades in an aft direction, and means for changing the direction of blade reaction against the Water of at least one of said rotor members, thereby changing the direction of thrust for maneuvering the craft.

17. A water craft having means for supporting, propelling and maneuvering the craft during planing operation, said means additionally functioning to maneuver and propel said craft during buoyant supported operation, said means including a plurality of rotors, each of said rotors being drivingly mounted on a shaft having an axis tilted with respect to the water surface, means for driving said rotors, means for movably positioning at least one of said rotors about an axis which is substantially rotor, whereby rotation of said rotors produces lift and propulsion of said craft and whereby movably positioning at least one of said rotors about said vertical axis provides maneuvering of the craft due to the change in direction of thrust produced by said blade-like members. 18. The water craft defined in claim 17 wherein said plurality of rotors comprises at least two pair of counterrotating rotors, at least one pair of said pairs of rotors being movably positioned with respect to said vertical axis and with respect to one another by said positioning means to provide planing hover operation of said craft.

19. Propelling and supporting means for a Water craft including at least one rotor having a hub portion and a plurality of blade-like members extending from said hub portion, driving means for said rotor, said rotor having an axis positioned at an angle with respect to the axis of said driving means, means for rotating the rotor axis about the axis of said driving means, flap-like members operatively positioned at the trailing edge of said bladelike members, and means for moving said flap-like members with respect to said blade-like members, whereby during planing operation of the craft less than one-half of said blade-like members are in contact with the water and at an angle substantially parallel to the surface thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,669,000 Filippi May 8, 1928 1,923,958 Wesnigk Aug. 22, 1933 3,075,727 Ellis et a1. Jan. 29, 1963 FOREIGN PATENTS 15,254 Great Britain June 25, 1903 (of 1902) 431 Great Britain July 29, 1909 (of 1909) 512,471 Belgium July 15, 1952 

1. PROPELLING AND SUPPORTING MEANS FOR A WATER CRAFT INCLUDING AT LEAST ONE ROTOR HAVING A HUB PORTION AND A PLURALITY OF BLADE-LIKE MEMBERS EXTENDING FROM SAID HUB PORTION AND AT AN ANGLE THERETO, DRIVING MEANS FOR SAID ROTOR, SAID ROTOR HAVING AN AXIS POSITIONED AT AN ANGLE WITH RESPECT TO THE AXIS OF SAID DRIVING MEANS, AND MEANS FOR ROTATING THE ROTOR AXIS ABOUT THE AXIS OF SAID DRIVING MEANS, WHEREBY LESS THAN ONE-HALF OF SAID BLADE-LIKE MEMBERS ARE IN CONTACT WITH THE WATER DURING PLANING OPERATION OF THE CRAFT. 